Brasília time, BRT (UTC−03:00)

The main time zone of Brazil corresponds to the time at the national capital city,
Brasília. All the other time zones are given as offsets to it.

In addition to the
Federal District (which includes Brasília), it comprises the states in the
Southeast,
South and
Northeast Regions, plus the states of
Goiás,
Tocantins,
Pará and
Amapá. The small islands mentioned above are excepted. Almost 94% of the Brazilian population live in this time zone, which covers about 60% of the country's land area.[1] The area comprises all six largest cities in Brazil (including Brasília).

Outside of summer time, it corresponds to
UTC−03:00. During summer time, it changes to
UTC−02:00, but this change is not followed by Northern and Northeastern states.

Brasília time −1 (UTC−04:00)

Outside of summer time, this time zone corresponds to
UTC−04:00; during summer time, it changes to
UTC−03:00, but this change is not followed by Northern states. This time zone is used in the states of
Mato Grosso,
Mato Grosso do Sul,
Rondônia,
Roraima, and most of
Amazonas. Although this time zone covers about 34% of the land area of Brazil (an area larger than
Argentina), little more than 5% of the country's population live there (about 11 million people, less than the city of
São Paulo).[1]

Until 2008, the areas of the state of
Pará west of the
Xingu River and north of the
Amazon River were also part of this time zone; then they joined the rest of the state in observing Brasília time (
UTC−03:00). Although other changes to Brazilian time zones enacted at that time have since been reverted (see below), Western and Northern Pará still remain in
UTC−03:00.

Brasília time −2 (UTC−05:00)

This time zone was reinstated in 2013, after having been abolished for over five years. It is used in the far-western tip of the country, which includes the entire state of
Acre and the southwestern portion of the state of
Amazonas (west of a line connecting the cities of
Tabatinga and
Porto Acre, but in practice a somewhat larger area, because all municipalities that are at least partially west of that line follow this time zone in their entirety). These areas cover only about 6% of the Brazilian territory (although that is still about the size of
France) and have only about 0.5% of the country's population (little more than 1 million people).[1]

On 24 June 2008, these areas advanced their clocks by an hour, so that they became part of the
UTC−04:00 time zone.[2] However, in a non-binding
referendum held on 31 October 2010, a slight majority of Acre voters voted in favour of returning the state to the UTC-05.[3] On 30 October 2013, Brazilian
PresidentDilma Rousseff enacted Law 12876, establishing that the time zone switch would occur on Sunday, 10 November 2013.[4] Since then, the state of Acre and 13 municipalities in the southwestern part of the state of Amazonas[5] are again 5 hours behind UTC.

Unofficial observance

Unofficially, 32 municipalities in
Mato Grosso[7] and three in
Goiás,[8] located in the
Araguaia valley, observe
UTC−03:00 all year. Therefore, these municipalities observe the legal time in the rest of their states only during summer time (in Mato Grosso) or during standard time (in Goiás). This practice started in
Barra do Garças in 1998. Banks and government services still observe the legal time in these locations.[9][10][11]